Adult patients (>18 years) with history of mild intermittent to moderate asthma according to the Global Initiative for Asthma (GINA) guidelines were enrolled. It was required a positive skin prick test (>3 mm) for at least two regional allergens. Patients were randomly assigned to receive lipoic acid or placebo for 60 days. Participants had an intermediate visit to the attending physician one month after initial of treatment to monitor adverse events and to undergo laboratory tests.